Date of Award
Master of Science
Industrial and Manufacturing Systems Engineering
Matthew C. Frank
This thesis presents a process planning methodology for orienting and fixturing bone prior to the rapid machining of custom bone implants. The motivation is to automatically create custom bone implant fragments that will fill voids caused by extreme trauma. Fixturing can be one of the biggest challenges of any manufacturing process, in particular, for custom components. "CNC-RP" is a Subtractive Rapid Prototyping (SRP) process which employs the concept of sacrificial supports for fixturing. The support structures are added to the CAD model prior to tool path planning and subsequently created during the machining process along with the other part features. This method of adding support structures has been proved successful for the machining of industrial components out of cylindrical stock material. Due to the unique position of the implant corresponding to the density distribution within natural bone (stock), it is a challenge to create the same support structures. An alternative approach has been identified which will uniquely address this problem by adding supports externally, in the form of metal screws.
A set of existing algorithms identify the harvesting site of the implant; the algorithms also yield the location and the direction of the support structures in the form of co-ordinates and vectors. The methodology presented in this work provides a novel method to physically add the support structures at precise position and direction utilizing a five axis fixture. Using the principles of inverse kinematics, the rotations and translations are determined. The resulting co-ordinates of the support positions are used to insert the supports.
Kuntal Hemant Barhate
Barhate, Kuntal Hemant, "Process planning for fixturing of custom machined implants" (2013). Graduate Theses and Dissertations. 13382.